support for .NET framework 3.5

Still have bugs

Net35/HandyControlDemo_Net35/Window/NoNonClientAreaDragableWindow.xaml.cs

@@ -0,0 +1,14 @@
+using System.Windows;
+
+namespace HandyControlDemo.Window
+{
+    public partial class NoNonClientAreaDragableWindow
+    {
+        public NoNonClientAreaDragableWindow()
+        {
+            InitializeComponent();
+        }
+
+        private void ButtonClose_OnClick(object sender, RoutedEventArgs e) => Close();
+    }
+}